Abstract
INTRODUCTION: By 2022, COVID-19 vaccine uptake in the USA had plateaued. We tested whether unvaccinated individuals in 2022 were wilfully avoiding vaccine information, or if they would voluntarily accept vaccine education. METHODS: In this double-blind, parallel, randomised educational study, we recruited US residents to participate in an online survey-experiment between 27 January 2022 and 25 February 2022. Subjects were first screened for vaccination status. Unvaccinated individuals were then separately invited into the survey. We developed video-based informational interventions that provide detailed, yet easy-to-grasp, explanations of mRNA vaccine technology, development, testing and safety protocols, and potential side effects. Participants were randomised into three groups: (1) a control group who watched an unrelated placebo video, (2) a 'video-optional' group for whom every informational video was optional and (3) a 'video-required' group for whom the vaccine-technology video was mandatory, but all other videos were optional. Primary endpoints were future COVID-19 vaccine uptake intentions, COVID-19 vaccine efficacy beliefs and COVID-19 vaccine side-effect concerns (all measured on a 100-point scale). Secondary endpoints measured information-seeking behaviour and trust in healthcare professionals. RESULTS: Relative to control (3014 participants), the video-optional group (1320 participants) exhibited a 0.09 standard deviation (95% CI 0.02 to 0.15) improvement in COVID-19 vaccine intentions, a 0.10 SD (95% CI 0.03 to 0.17) improvement in COVID-19 vaccine-efficacy beliefs, and a 0.14 SD (95% CI 0.07 to 0.21) improvement in COVID-19 side-effect concerns. The video-required group (2756 participants) yielded improvements, relative to control, of 0.07, 0.18 and 0.08 SDs in the respective categories (95% CIs 0.02 to 0.12, 0.13 to 0.23, 0.03 to 0.13). 55%-60% of the participants in both treatment groups watched optional videos. CONCLUSIONS: Wilful avoidance of vaccine information does not appear to explain entrenched vaccine hesitancy. Impartial and detailed information may be an effective communication and policy tool. TRIAL REGISTRATION NUMBERS: ISRCTN98065390 and American Economic Association Trial Registry (AEARCTR0008909).